To study the effect of adding tomato paste (as a natural acidulant) to Mozzarella cheese milk on the yield, chemical composition, texture profile, and organoleptic properties of the resultant cheeses. Four treatments were applied: cheese made with a starter culture (control), and the rest three treatments were acidified by tomato paste to pH 6.0, 5.8, and 5, 6, respectively. The resultant cheese of all treatments was evaluated when fresh and after 60 days of storage. Results showed that the addition of tomato paste increased the yield slightly, when fresh and at the end of the storage period, compared with the control one. A direct relationship was noticed between the gross chemical composition of Mozzarella cheese and both the combined action of pH milk and tomato paste added. Texture profile results showed that the control cheese had higher values in all parameters than in the tomato paste treatments except for cohesiveness and springiness values either when fresh or after 60 days of storage. Control cheese had organoleptic properties lower than the tomato paste treatments during storage and adding the tomato paste to cheese milk to reach pH 5.6 gave the best organoleptic properties of Mozzarella cheese.